DS2154
Receive Sync [RSYNC]. An extracted pulse, one RCLK wide, is output at this pin which identifies either
frame or CAS/CRC multiframe boundaries. If the receive side elastic store is enabled, then this pin can be
enabled to be an input at which a frame or multiframe boundary pulse synchronous with RSYSCLK is
applied.
Receive Frame Sync [RFSYNC]. An extracted 8 kHz pulse, one RCLK wide, is output at this pin which
identifies frame boundaries.
Receive Multiframe Sync [RMSYNC]. An extracted pulse, one RSYSCLK wide, is output at this pin
which identifies multiframe boundaries. If the receive side elastic store is disabled, then this output will
output multiframe boundaries associated with RCLK.
Receive Data [RDATA]. Updated on the rising edge of RCLK with the data out of the receive side
framer.
Receive System Clock [RSYSCLK]. 1.544 MHz or 2.048 MHz clock. Only used when the elastic store
function is enabled. Should be tied low in applications that do not use the elastic store. Can be burst at
rates up to 8.192 MHz.
Receive Signaling Output [RSIG]. Outputs signaling bits in a PCM format. Updated on rising edges of
RCLK when the receive side elastic store is disabled. Updated on the rising edges of RSYSCLK when the
receive side elastic store is enabled. See Section 13 for timing examples.
Receive Loss of Sync / Loss of Transmit Clock [RLOS/LOTC]. A dual function output that is
controlled by the TCR2.0 control bit. This pin can be programmed to either toggle high when the
synchronizer is searching for the frame and multiframe or to toggle high if the TCLK pin has not been
toggled for 5 µs.
Receive Carrier Loss [RCL]. Set high when the line interface detects a loss of carrier. [Note: a test
mode exists to allow the DS2154 to detect carrier loss at RPOSI and RNEGI in place of detection at RTIP
and RRING].
Receive Signaling Freeze [RSIGF]. Set high when the signaling data is frozen via either automatic or
manual intervention. Used to alert downstream equipment of the condition.
8 MHz Clock [8MCLK]. 8.192 MHz output clock that is referenced to the clock that is output at the
RCLK pin.
Receive Positive Data Output [RPOSO]. Updated on the rising edge of RCLKO with the bipolar data
out of the line interface. This pin is normally tied to RPOSI.
Receive Negative Data Output [RNEGO]. Updated on the rising edge of RCLKO with the bipolar data
out of the line interface. This pin is normally tied to RNEGI.
Receive Clock Output [RCLKO]. Buffered recovered clock from the E1 line. This pin is normally tied
to RCLKI.
Receive Positive Data Input [RPOSI]. Sampled on the falling edge of RCLKI for data to be clocked
through the receive side framer. RPOSI and RNEGI can be tied together for a NRZ interface. Can be
internally connected to RPOSO by tying the LIUC pin high.
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DALLAS [ DALLAS SEMICONDUCTOR ]
